摘要
为了探讨外源一氧化氮(NO)对镉(Cd)胁迫下高羊茅(Festuca arundinacea)生理响应的调节机制,采用水培方法,研究了不同浓度的NO供体硝普钠(SNP)对100μmol·L^(-1)CdCl_2胁迫下高羊茅幼苗生长、光合特性及矿质元素吸收的影响。结果表明:在Cd胁迫下,外施SNP能显著增加高羊茅叶片中NO含量,同时增加植株干重,提高根生长率和根系活力;增加叶片中叶绿素和类胡萝卜素的含量,提高净光合速率(P_n)、增强PSⅡ反应中心最大光能转换效率(F_v/F_m)等指标,显著增强了高羊茅地上部分与根对Ca,Mg,Zn和Fe的吸收,抑制了Cd向地上部分的转运。综合各项指标来看,100μmol·L^(-1)SNP效果最好,能够显著改善高羊茅叶片的光合活性,维持植株体内矿质元素平衡,从而缓解Cd胁迫对高羊茅光合作用的抑制,促进其生长并提高其耐受性。
In order to discuss the regulatory mechanism of nitric oxide （NO） on Festuca arundinacea physi- ological response under Cd stress, a hydroponic experiment was conducted to investigate the effects of dif- ferent concentrations of sodium nitroprusside （SNP, NO donor） on the physiological performance of F. arundinacea under 100 μmol · L 1 CdC12 stress. These physiological performances included the growth, photosynthetic characteristics and mineral element contents of F. arunclinacea. The results showed that exogenous SNP not only significantly increased the NO contents of leaves, plant dry weight, root growth rate and root activity of F. arundinacea under Cd stress; but also increased leaf chlorophylls and carote- holds contents, net photosynthetic rate （Pn）, PSⅡ maximum photochemical efficiency （Fv/Fm）. In addi- tion, SNP significantly enhanced the calcium （Ca）, magnesium （Mg）, iron（Fe）, zinc （Zn） contents of shoots and roots, inhibited the transportation of Cd from root to shoot. These results showed that adding exogenous nitric oxide could increase the resistance of F. arundinacea under Cd stress. Comprehensive view of the indicators indicated that 100 μmol · L-1SNP had the best effect on improving photosynthetic activity and maintaining the mineral nutrition balance, then the inhibition of photosynthesis caused by Cd stress was alleviated and the tolerance of F. arundinacea increased.
出处
《草地学报》
CAS
CSCD
北大核心
2015年第2期338-345,共8页
Acta Agrestia Sinica
基金
四川省科技计划项目(2012FZ0083)资助
关键词
一氧化氮
高羊茅
镉伤害
植物修复
Nitric oxide
F. arundinacea Cadmium stress
Phytoremediation
